Sensor device and method

ABSTRACT

The sensor device has a housing. The housing is made of a material having a first high heat-conductivity index. A holder is attached to the housing and made of a material with a second low heat-conductivity index that is substantially lower than the first high heat conductivity index. The holder holds a peltier element and is connected to a power source so that the element has a cooled layer and a heated layer. A rotatable roller is in operative engagement with the layer so that the layer cools the roller. The roller may be rolled on the skin of the patient to determine the scope and effect of anesthetic treatment.

TECHNICAL FIELD

The present invention relates to a cooled sensor device and a method ofusing the device.

BACKGROUND AND SUMMARY OF THE INVENTION

Physicians/surgeons and other medical professionals often need toadminister anesthetics before conducting surgery and other operations.However, it is sometimes difficult to know how effective the anestheticdrugs are and the size of the area affected. For example, whenadministering anesthetics to the spine it is often important todetermine how high up on the spine the anesthetics have traveled. Somemedical professionals test this by applying ice cubes or cold rubberalcohol to skin along the spine and the patient is asked whether the icecan be felt or not. This method is messy and unreliable.

It is also necessary for the medical professional to repeatedly gobetween a freezer and the patient since the ice melts at roomtemperature. Other professionals pinch the patient with a tool or useneedles. These methods are sometimes not comfortable for the patient andnot so reliable as they influence other nerve centers also. Cold gasspray device have also been used but they are uneconomic, smell bad andare not good for the environment. There is a need for a more reliableand efficient method of determining how much of the area anaesthetizedis affected by the anesthetics.

The present invention solves the above-outlined problems. Firstly, thepresent invention has an even low surface temperature device that holdsthe temperature constant by a constant power supply. Secondly, thesurface temperature can be held, for example, at about −5 down to −20 Cdepending on the power used. This is more effective than melting ice atabout 0 C. Thus, the present invention is a more effective and reliablemethod and suitable as a standard method for testing.

More particularly, the sensor device of the present invention has ahousing with a flanged section that has a threaded outer section. Theflanged section is made of a material that has a high heat conductivityindex.

A holder or nut is attached to the outer section and made of a materialwith a low heat conductivity index that is substantially lower than thefirst high heat conductivity index. The holder holds a peltier elementis held to the outer section. The peltier element is connected to apower source so that the element has a cooled outer layer and a heatedinner layer. The inner layer is in contact with the section and theouter layer may be applied on to the skin of the patient to determinethe scope and effect of anesthetic treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional side view of a first embodiment of thesensor device of the present invention;

FIG. 2 is a cross-sectional side view of a second embodiment of thesensor device of the present invention;

FIG. 3 is a side view of the sensor device along line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional side view of a third embodiment of thesensor device of the present invention;

FIG. 5 is a cross-sectional side view of the sensor device along line5-5 of FIG. 4; and

FIG. 6 is a detailed of the curved peltier element of the sensor deviceof the present invention.

DETAILED DESCRIPTION

With reference to FIG. 1, a first embodiment of the elongate sensordevice 10 is shown that may be used for sensing nerve reactions of apatient by using a cold element, as explained below. The cooling elementmay hold a constant temperature of about −5 to −15 C or any othersuitable temperature range. Only a small cooling power is required andit is often sufficient to use one peltier element. However, even lowertemperatures can be accomplished by applying two peltier elements on topof each other.

The device 10 is useful for determining the area affected by, forexample, anesthesia on the body of the patient. The device 10 has anelongate housing 12 that may contain a power source 14, such asbatteries, held in place by a removable lid 16. A coupling 17 isarranged in the lid 16 and the coupling 17 is suitable for connecting abattery charger to the battery. A mid-portion 18 of the housing 12 has aswitch 20 for turning on and off the device 10. The housing 12 may alsohave a light emission diode 22 that indicates whether the device 10 isturned on or not. The device 10 also has an enlarged cooling segment 24that terminates at a threaded outer end 26. The segment 24 may containflanges or segments to maximize a surface area 28 of the segment 24. Thesegment 24 may be made of an extruded aluminum or any other suitablematerial with a high heat-conductivity index.

The segment 24 may also be hollow and contain a volume of a material orsubstance 27, e.g. cooling liquid or water that has a higher thermalcapacity than the material in segment 24. In this way, more heat can beabsorbed during a limited time with very limited temperature increase insegment 24, especially when the ambient temperature is high and thecooling effect in the flanges 28 is lower. This is an advantage when thedevice 10 is used intermittently and the ambient air temperature is highthat may result in a lower cooling effect from the flanges 28.

A plastic nut or holder 30 may be removably attached to a threaded end26 of the segment 24. The holder 30 may be made of any material with alow heat-conductivity such as glass-fiber composites or plastics. Thenut 30 may have a slanted inner diameter 34 to hold a cover plate 36 anda peltier element 38 against the threaded end 32. The plate 36 may beused to protect the element 38 from damage such as scratches, corrosionand wear during use and cleaning of the device 10.

The peltier element 38 is electrically connected, via wires 39, to anelectrical circuit 40 that is turn is powered by the power source 14.The element 38 may have a plurality of layers and when the element 38 iselectrically connected the element 38 makes a top layer 41 substantiallycooler than a bottom layer 43. For example, the layer 41 may have atemperature range of −5 to −15 C while the opposite bottom layer 43 mayhave a temperature of +30 to +50 C depending on the power applied to thepeltier element 38. In a way, the element 38 is opposite to that of aconventional thermo-element.

One important function of the solid segment 24 is to lead away the heatgenerated in the bottom layer 43 because an upper surface 45 of the end26 of the segment 24 is, preferably, in direct contact with the layer43.

Because the segment 24 has a large surface area 28 and is made of amaterial with high heat conductivity, the segment 24 may efficientlylead away the heat generated by the element 38 so as to increase theefficiency of the element 38. By maintaining the temperature of thelayer 43 at about +35 C, it is possible to operate the element 38 athalf the full effect so that the temperature difference between the coolside and the warm side is about 35-45 degrees. When operated at a fullpower, the temperature difference between the cooled layer 41 and theheated layer 43 may be as high as 78 C or higher. The use of the segment24 thus saves on the energy consumption of the device 10.

In operation, the user may turn on the device 10 by switching on theswitch 20. The current runs through the element 38 so that a substantialtemperature difference is created between the layer 41 and the layer 43and so that the layer 41 becomes very cold. Since the element 36 has arelatively high conductivity, an upper surface 47 of the element 36 alsobecomes cold. The surface 47 is applied to the patient who has beentreated with anesthesia, or any other treatment, to determine if thepatient can feel the cold surface 47 that is applied directly on theskin of the patient. When the effect of the anesthesia has beendetermined, the medical professional may turn off the device 10 byswitching the switch 20 to the off mode. An automatic switch-off after asuitable time can be arranged in the switch function 20 in order to savethe batteries.

As indicated above, because the segment 24 is solid and has a largesurface area 28 it may be used to cool off the heated layer 43 of theelement 38. The heat from the layer 43 is led into the segment 24 viathe surface 45. In this way, the surface 41 may be maintained at a lowtemperature while keeping the temperature difference between the layers41, 43, and energy consumption of the device 10, the same. It isimportant that the holder 30 is made of a material with low heatconductivity so that no heat is transferred from the layer 43 to thecooled layer 41 and the protective sheet 36.

FIGS. 2-3 are views of a device 11 with a roller 24 made of a materialwith a high heat conductivity that is cooled by built in peltierelements 38 and 38.1. In the roller 24 is assembled a number of peltierelements with the warm side 43 facing against the inner of the rollerand the cold side 41 facing against circular segments 42 on the outside,which are built into a circular ring 36, aimed at rolling on the skin ofa patient for testing the anesthetic effects. Preferably, both the ring36 and the segments 41 are made of material with high heat conductivity.

The roller 24, which can be rotated in bearings 32, can be connected byelectrical contact slide rings 33 to a power source such as the battery14 in the handle 12, via connecting wires 37 in the handle and wires 39in the roller to the peltier elements 38 in the roller 24.

The upper part of the roller ring 36 directed from the lower area aimedat contacting to the skin of the patient, is heat isolated by applyingan isolation material 29 between the ring 36 and an inside of the handle12 and handle arms 34 Between the peltier elements 38, heat isolation 30can be arranged between the roller 24 and the ring 36. The wires 37 fromthe peltier elements 38 can be connected via an electrical system 40 toa switch 20, a diode light 22 and to the power source 14.

At the end of the handle 12, which preferably can be made ofelectrically isolated material, such as plastics, is a lid 16 disposedin order to close in the battery and a coupling 17 suitable forconnecting the rechargeable batteries 14 to an external battery charger.The peltier elements can be connected in parallel in order to get thesame voltage and power from the battery 14.

By using peltier elements, such as the peltier elements 38.1, with acurved radius that corresponds to the inner diameter of the ring 36,improved heat conduction and even distributed temperature may beachieved by eliminating the segment 42. The cooling of the roller 24 isreached by cooling flanges 28 arranged on the sides of the roller,increasing the surface to the ambient air and also getting better heattransmission by higher air speed when the roller is rotated.

By introducing a volume 25 in the roller 24 and fill it with a materialwith higher thermal capacity 27, than the material of the roller 24,more heat from the peltier elements can be absorbed with limitedtemperature increase during a limited time. This is an advantage whenthe device 11 is used intermittently and the ambient air temperature ishigh, resulting in lower cooling effect from the flanges 28.

FIGS. 4-5 are views of a device 13 with a roller 36 made of a materialwith high heat conductivity that is cooled by the external peltierelements 38.1 that are in contact with the roller surface via segments42. In the housing 24 a number of peltier elements 38.1 are assembledwith the warm side 43 facing outwardly against the housing 24. The coldside 41 is facing against circular segments 42 on the inside against theroller circular ring 36, aimed at rolling on the skin of the patient fortesting the anesthetic and other effects. Both the ring 36 and thesegments 42 may be made of material with high heat conductivity so thatthey can be quickly and effectively cooled by the peltier elements 38.1.

The roller 36 can be rotated in bearings, by sliding against thecircular segments 42 assembled to the housing 24 by holders 30 and alsoholding the peltier elements 38.1 in place against the housing 24. Theroller 36 with an inside insulation material 29 is cooled by the contactwith the cold circular segments 42.

The peltier elements 38.1 are connected to the battery 14 in the handle12 via an electrical system 40 by connect wires 37 in the handle andhousing 24. The electrical system 40 in the mid-portion 18 of thehousing 12 has a switch 20 for turning on and off the device 13. Thehousing 12 may also have a light emission diode 22 that indicateswhether the device 13 is turned on or not. An automatic switch-off aftera suitable time can be arranged in the switch function 20 in order tosave the batteries.

At the end of the handle 12, which preferably can be made ofelectrically insulated material, such as plastic, is a lid 16 in orderto close in the battery and a coupling 17 suitable for connecting therechargeable batteries 14 to an external battery charger. The peltierelements can be connected in parallel in order to get the same voltageand power from the battery 14.

By using peltier elements 38.1 with a curved radius that corresponds tothe outer radius of the bearing segment 42, improved heat conduction andeven distributed temperature are accomplished. The cooling of thehousing 24 may be achieved by the cooling flanges 28 disposed on thesides of the housing to increase the surface to the ambient air thatresults in increased cooling effect. By introducing a volume 25 in thehousing 24 and fill it with a material 27 with higher thermal capacitythan the housing material, more heat from the peltier elements can beabsorbed with limited temperature increase in the housing 24 during alimited time. This is an advantage when the device 13 is usedintermittently and the ambient air temperature is high resulting inlower cooling effect from the flanges 28.

FIG. 6 is detailed view that shows the curved peltier element 38.1 andthe surfaces 43 and 41 on each side of the element 38.1. The roller 36is disposed radially inside the element 38.1 so that it is cooled by thesurface 41. In this way, the roller 36, which is cooled by the peltierelements 38.1, may be rolled on the skin of the patient to be tested.

While the present invention has been described in accordance withpreferred compositions and embodiments, it is to be understood thatcertain substitutions and alterations may be made thereto withoutdeparting from the spirit and scope of the following claims.

1. A sensor device comprising: a roller (36) in operative engagementwith a housing (24); a peltier element (38, 38.1) attached to thehousing (24) and having a cooled surface (41) and a heated surface (43),the peltier element being connected to a power source (14) to obtain atemperature difference between the cooled surface and the heated surfacethereof, the surface (41) being cooled by the peltier element and theinner surface (43) being heated by the peltier element and directed in adirection that is opposite the direction of the surface (41), thesurface (41) being in operative engagement with the roller (36) to coolthe roller (36).
 2. The sensor device according to claim 1 wherein heatis led away from the heated surface (43) and the surface (43) is incontact with the housing (24) that has a high heat conductivity andformed with an area of flanges (28) in order to increase heat transferto another medium that is in contact with the flanges (28).
 3. Thesensor device according to claim 1 wherein the segment (24) is inoperative thermal contact with a volume (25) containing another material(27) that has high thermal capacity and stores heat from the innersurface (43).
 4. The sensor device according to claim 1 wherein apeltier element (38, 38.1) is held against the housing (24) by a holder30 made of a material with low heat conductivity.
 5. The sensor deviceaccording to claim 1 wherein a cover plate (42), in contact with thepeltier element, bears against a surface of the roller (36).
 6. Thesensor device according to claim 5 wherein the peltier element (38,38.1) is in operative engagement with the cylindrical outer surface ofthe roller (36).
 7. The sensor device according to claim 1 wherein theroller (36) is rotatably attached to a housing (24) and is made of amaterial with high heat conductivity.
 8. The sensor device according toclaim 6 wherein the roller (36) is in contact with an isolation material(29) that is cooled by the peltier element (38.1).
 9. A sensor devicecomprising: a peltier element (38) held by a holder (30) attached bythreads to an outer end (26) of a housing (24); the peltier element (38)being in contact with the housing (24) and disposed on the outer end(26); the peltier element having a cooled surface (41) and a heatedsurface (43), the peltier element being connected to a power source (14)to obtain a temperature difference between the cooled surface and theheated surface thereof, the surface (41) being cooled by the peltierelement and the inner surface (43) being heated by the peltier elementand directed in a direction that is opposite the direction of thesurface (41); the surface (41) providing a cooled testing surface, thesurface (43) being in contact with the housing (24) that has a high heatconductivity for effectively transferring heat from the surface (43) andthe housing (24) having a volume for absorbing the heat, the housinghaving a surface formed with an area of flanges (28) in order toincrease heat transfer to another medium that is in contact with theflanges (28); the holder (30) being made from a material with a low heatconductivity, that is lower than the high heat conductivity of thehousing (24), to avoid heat transfer between the cold surface (41) andthe hot surface (43).
 10. The sensor device according to claim 9 whereinthe sensor device has a cover plate (36) held by the holder (30). 11.The sensor device according to claim 9 wherein the housing has a cavity(25) defined therein, the cavity (25) contains a material (27) that hasa high thermal capacity higher than a thermal capacity of the housing(24) for storing heat from the inner surface (43).